CN114026160A

CN114026160A - Blowing agent blends for thermoplastic polymers

Info

Publication number: CN114026160A
Application number: CN202080046780.7A
Authority: CN
Inventors: K·康托马里斯
Original assignee: Chemours Co FC LLC
Current assignee: Chemours Co FC LLC
Priority date: 2019-06-24
Filing date: 2020-06-23
Publication date: 2022-02-08
Also published as: US20220235193A1; JP2022539332A; CA3138904A1; EP3986961A1; JP7576580B2; WO2020263775A1

Abstract

本发明涉及包含HFO‑1336mzz‑Z、甲酸甲酯和任选的HFC‑152a的共混物作为用于热塑性聚合物(例如聚苯乙烯)的发泡剂的用途。The present invention relates to the use of a blend comprising HFO-1336mzz-Z, methyl formate and optionally HFC-152a as a blowing agent for thermoplastic polymers such as polystyrene.

Description

Blowing agent blends for thermoplastic polymers

Technical Field

The present invention relates to the use of a blend comprising HFO-1336mzz-Z, methyl formate and optionally HFC-152a as a blowing agent for thermoplastic polymers, such as polystyrene.

Background

Chlorofluorocarbons (i.e., CFCs) have historically been used as blowing agents to produce various types of foams. Generally, CFCs produce foams that exhibit good thermal insulation, low flammability, and excellent dimensional stability. However, despite these advantages, CFCs have become disfavored because of their effect on ozone destruction in the stratosphere and their effect on contributing to global warming. Therefore, there is a need for blowing agents that have both low ODP (ozone depletion potential) and GWP (global warming potential).

Disclosure of Invention

The present application provides, inter alia, a process for preparing a thermoplastic polymer foam, the process comprising:

(a) providing a foamable composition comprising a thermoplastic polymer and a blowing agent, wherein the blowing agent comprises from about 30 wt% to about 85 wt% Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and from about 10 wt% to about 40 wt% methyl formate; and

(b) expanding the foamable composition to produce the thermoplastic polymer foam.

The present application also provides a thermoplastic polymer foam comprising:

(a) a thermoplastic polymer selected from the group consisting of: polystyrene homopolymers, polystyrene copolymers and styrene-acrylonitrile copolymers, or blends thereof; and

(b) a blowing agent comprising 30 to 85 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and 10 to 40 weight percent methyl formate.

In some embodiments, the thermoplastic polymer foam provided herein is prepared according to one or more of the methods described herein.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Methods and materials for use in the present invention are described herein; in addition, suitable methods and materials known in the art can also be used. The materials, methods, and examples are illustrative only and not intended to be limiting. All publications, patent applications, patents, sequences, database entries, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control.

Drawings

FIG. 1 compares the solubility of HFO-1336 mzz-Z/methyl formate blends containing 20 wt.% methyl formate in polystyrene having a Melt Flow Index (MFI) of 5.00g/10min at 176 ℃ with the solubility of pure HFO-1336mzz-Z in polystyrene.

FIG. 2 compares the solubility of HFO-1336mzz-Z/HFC-152 a/methyl formate blends in polystyrene homopolymer having an MFI of 5.00g/10min at 176 ℃ with the solubility of HFO-1336mzz-Z/HFC-152a (50 wt%/50 wt%) blends.

Detailed Description

Existing agents with high Global Warming Potential (GWP) for expanding thermoplastic foams, such as extruded polystyrene foam (XPS), are under regulatory pressure. Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene (i.e., HFO-1336mzz-Z) is in principle useful as a low GWP agent for expanding polystyrene (or other thermoplastic polymers) into foams having high thermal insulation capability. However, HFO-1336mzz-Z has low solubility in softened polystyrene under the operating conditions of existing extrusion processes. Thus, they will result in sub-optimal foam properties (e.g., higher than desired foam density).

Blowing agents used to expand thermoplastic foams (e.g., polystyrene foams) must be sufficiently soluble in molten thermoplastic polymers (e.g., polystyrene resins) under foam-forming conditions such that sufficient volume of blowing agent is available during the foam expansion and cooling stages to form cells and reduce the effective foam density to a target value. The presence of an expanding agent in excess of its solubility can lead to foam defects.

As described herein, it has been unexpectedly discovered that blends of HFO-1336mzz-Z with methyl formate can exhibit a solubility in softened polystyrene that significantly exceeds the solubility of pure HFO-1336mzz-Z under the same conditions. For example, the solubility of pure HFO-1336mzz-Z in a softened polystyrene homopolymer having a Melt Flow Index (MFI) of 5.0g/10min at 179 ℃ and 1,682psia was measured as 5.82g/100g of polystyrene (i.e., 5.82 parts solute per 100 parts resin by mass or 5.82 phr). In contrast, HFO-1336 mzz-Z/methyl formate blends containing 20 wt.% methyl formate have a solubility of 13.14g/100g of polystyrene in the same polystyrene at the same temperature and pressure or 125.7% higher than the solubility of pure HFO-1336 mzz-Z.

It has also been unexpectedly found that a ternary blend of HFO-1336mzz-Z/HFC-152 a/methyl formate (40 wt%/20 wt%, respectively) exhibits a solubility in softened polystyrene that significantly exceeds the solubility of a binary blend of HFO-1336mzz-Z/HFC-152a (50 wt%/50 wt%) under the same conditions. For example, a HFO-1336mzz-Z/HFC-152a blend containing 50 wt% HFC-152a has a solubility of 9.58g/100g of polystyrene (i.e., 9.58phr) in a softened polystyrene homopolymer having a Melt Flow Index (MFI) of 5.0g/10min at 179 ℃ and 1,336 psia. In contrast, the solubility of the ternary HFO-1336mzz-Z/HFC-152 a/methyl formate (40 wt%/20 wt%, respectively) blend has a solubility of about 12.80g/100g of polystyrene in the same polystyrene at the same temperature and the same pressure (1,336psia) (i.e., 33.61% higher than the solubility of the binary HFO-1336mzz-Z/HFC-152a (50 wt%/50 wt%) blend). It has also been found that a ternary HFO-1336mzz-Z/HFC-152 a/methyl formate (33.33 wt%/33.33 wt%) blend has a solubility of about 16.25g/100g of polystyrene in the same polystyrene at the same temperature and the same pressure (1,336psia) (i.e., 69.62% greater than the solubility of a binary HFO-1336mzz-Z/HFC-152a (50 wt%/50 wt%) blend).

Thus, provided herein and optionally further comprising at least one additional compound provided herein (e.g., selected from the group consisting of HFO, HCFO, HFC, HFE, HCFC, CFC, CO)₂、N₂Blends of olefins, hydrochloroolefins, chlorinated hydrocarbons, organic acids, alcohols, hydrocarbons, ethers, aldehydes, ketones, water, ethyl formate, formic acid and trans-1, 2-Dichloroethylene (DCE) may be used as blowing agents with low or medium GWP for expanding thermoplastic foams, including extruded polystyrene foams.

Definitions and abbreviations

As used herein, the terms "comprises," "comprising," "includes," "including," "has," "having" or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, "or" means an inclusive or and not an exclusive or. For example, condition a or B satisfies one of the following conditions: a is true (or present) and B is false (or not present), a is false (or not present) and B is true (or present), and both a and B are true (or present).

In addition, the use of "a" or "an" is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. The description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

As used herein, the term "about" is intended to account for variations due to experimental error (e.g., plus or minus about 10% of the indicated value). Unless otherwise expressly stated, all measurements reported herein are to be understood as being modified by the term "about", whether or not that term is expressly used.

The term "consisting of," as used herein, does not include any unspecified elements, steps or ingredients. If in the claims that follow, no protection is intended for materials other than those described except for impurities normally associated therewith. The phrase "consisting of" or "consisting of" when it appears in a clause of the subject matter of the claims, rather than immediately following the preamble, limits only the elements described in that clause; other elements are not excluded from the entire claims.

As used herein, the term "consisting essentially of is used to define compositions, methods that include materials, steps, features, components, or elements in addition to those disclosed in the literature, provided that such additional included materials, steps, features, components, or elements do not materially affect one or more of the basic and novel features of the claimed invention, particularly the mode of action, which achieves a desired result in any one of the methods of the invention. The term "consisting essentially of" or "consisting essentially of occupies an intermediate position between" comprising "and" consisting of.

When an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and/or lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

Global Warming Potential (GWP) is an index for estimating relative global warming contribution due to atmospheric emission of one kilogram of a specific greenhouse gas, compared to emission of one kilogram of carbon dioxide. GWP can be calculated over different time ranges, showing the effect on atmospheric lifetime for a given gas. For GWP in the 100 year time frame is usually the reference value.

As used herein, the term "ozone depletion potential" (ODP) is defined in "scientific assessment of ozone depletion, 2002, report of the world weather association's global ozone research and monitoring program", section 1.4.4, pages 1.28 to 1.31 (see section one). ODP represents the expected degree of ozone depletion in the stratosphere on a mass basis for compounds relative to trichlorofluoromethane (CFC-11).

The following abbreviations may be used herein:

CFC: chlorofluorocarbons

GWP: global warming potential

HCFC: hydrochlorofluorocarbons

HCFO: hydrochlorofluoroalkenes

HFC: hydrofluorocarbons

HFE: hydrofluoroethers

HFO: hydrofluoroolefins

HFC-152 a: 1, 1-difluoroethane

HFO-1336mzz-Z or 1336 mzz-Z: z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene

MFI: melt flow index

ODP: ozone depletion potential

PS: polystyrene

wt%: weight% or weight percentage

Process and foam of the invention

The present application provides a process for preparing a thermoplastic polymer foam.

In some embodiments, the methods provided herein comprise:

(a) providing a foamable composition comprising a thermoplastic polymer and a blowing agent, wherein the blowing agent comprises from about 95 wt% to about 1 wt% Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and from about 1 wt% to about 95 wt% methyl formate; and

In some embodiments, the solubility of the blowing agent in the polymer is greater than the solubility of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene alone in the polymer.

In some embodiments, the blowing agent comprises from about 90 to about 5 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, for example, from about 90% to about 10%, from about 90% to about 30%, from about 90% to about 50%, from about 90% to about 70%, from about 70% to about 5%, from about 70% to about 10%, from about 70% to about 30%, from about 70% to about 50%, from about 50% to about 5%, from about 50% to about 10%, from about 50% to about 30%, from about 30% to about 5%, from about 30% to about 10%, or from about 10% to about 5% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 75% to about 85% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises about 80 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 30% to about 45% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises about 35% to about 40% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 30% to about 40% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 30% to about 35% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 10% to about 95% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 30% to about 85% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises about 20% to about 60% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises from about 25% to about 55% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises about 80 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises about 40 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene. In some embodiments, the blowing agent comprises about 33 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

In some embodiments, the blowing agent comprises from about 1% to about 90% by weight methyl formate, for example from about 1% to about 70%, from about 1% to about 50%, from about 1% to about 30%, from about 1% to about 10%, from about 10% to about 90%, from about 10% to about 70%, from about 10% to about 50%, from about 10% to about 30%, from about 30% to about 90%, from about 30% to about 70%, from about 30% to about 50%, from about 50% to about 90%, from about 50% to about 70%, or from about 70% to about 90% by weight methyl formate. In some embodiments, the blowing agent comprises from about 5 wt.% to about 45 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 5 wt.% to about 40 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 10 wt.% to about 40 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 10 wt.% to about 25 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 5 wt.% to about 25 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 15 wt.% to about 25 wt.% methyl formate. In some embodiments, the blowing agent comprises about 20 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 15 wt.% to about 35 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 20 wt.% to about 35 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 15 wt.% to about 25 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 18 wt.% to about 22 wt.% methyl formate. In some embodiments, the blowing agent comprises from about 30 wt.% to about 35 wt.% methyl formate. In some embodiments, the blowing agent comprises about 20 wt.% methyl formate. In some embodiments, the blowing agent comprises about 33 weight percent methyl formate.

In some embodiments, the blowing agent comprises up to about 80 wt% Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, for example up to about 70 wt%, 60 wt%, 50 wt%, 40 wt%, 30 wt%, 20 wt%, or 10 wt% Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

In some embodiments, the blowing agent comprises up to about 35 wt.% methyl formate, for example up to about 33 wt.%, 25 wt.%, 20 wt.%, 15 wt.%, 10 wt.%, 5 wt.%, or 1 wt.% methyl formate.

In some embodiments, the blowing agent comprises up to about 80 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and up to about 33 weight percent methyl formate.

In some embodiments, the blowing agent comprises up to about 80 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and up to about 20 weight percent methyl formate.

In some embodiments, the blowing agent consists essentially of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and methyl formate. In some embodiments, the blowing agent consists of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and methyl formate.

In some embodiments, blowing agents provided herein further comprise HFC-152 a.

In some embodiments, blowing agents comprising HFC-152a have a solubility in the polymer that is greater than the solubility of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene alone in the polymer. In some embodiments, the blowing agent comprising HFC-152a has a solubility in the polymer that is greater than the solubility of the mixture of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and HFC-152a (i.e., in the absence of methyl formate) in the polymer.

In some embodiments, blowing agents comprising HFC-152a comprise from about 5% to about 60% by weight Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, for example from about 5% to about 40%, from about 5% to about 20%, from about 5% to about 10%, from about 10% to about 60%, from about 10% to about 40%, from about 10% to about 20%, from about 20% to about 60%, from about 20% to about 40%, or from about 40% to about 60% by weight Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

In some embodiments, the blowing agent comprises from about 20 wt% to 80 wt% HFC-152 a. In some embodiments, the blowing agent comprises from about 30 to 70 weight percent HFC-152 a. In some embodiments, the blowing agent comprises from about 30 wt% to about 45 wt% HFC-152 a. In some embodiments, the blowing agent comprises from about 30 to 40 weight percent HFC-152 a. In some embodiments, the blowing agent comprises about 40 wt% HFC-152 a. In some embodiments, the blowing agent comprises from about 30 to 35 weight percent HFC-152 a. In some embodiments, the blowing agent comprises about 33 wt% HFC-152 a.

In some embodiments, blowing agents comprising HFC-152a comprise from about 1% to about 25% by weight methyl formate, for example from about 1% to about 20%, from about 1% to about 15%, from about 1% to about 10%, from about 1% to about 5%, from about 5% to about 25%, from about 5% to about 20%, from about 5% to about 15%, from about 5% to about 10%, from about 10% to about 25%, from about 10% to about 20%, from about 10% to about 15%, from about 15% to about 25%, from about 15% to about 20%, from about 20% to about 25% by weight methyl formate. In some embodiments, blowing agents comprising HFC-152a comprise from about l weight percent to about 20 weight percent methyl formate.

In some embodiments, blowing agents comprising HFC-152a comprise from about 5 wt% to about 95 wt% HFC-152a, such as from about 5 wt% to about 80 wt%, from about 5 wt% to about 50 wt%, from about 5 wt% to about 25 wt%, from about 5 wt% to about 10 wt%, from about 10 wt% to about 95 wt%, from about 10 wt% to about 80 wt%, from about 10 wt% to about 50 wt%, from about 10 wt% to about 25 wt%, from about 25 wt% to about 95 wt%, from about 25 wt% to about 80 wt%, from about 25 wt% to about 50 wt%, from about 50 wt% to about 95 wt%, from about 50 wt% to about 80 wt%, or from about 80 wt% to about 95 wt% HFC-152 a. In some embodiments, blowing agents comprising HFC-152a comprise from about 20 weight percent to about 80 weight percent HFC-152 a. In some embodiments, blowing agents comprising HFC-152a comprise from about 50 weight percent to about 70 weight percent HFC-152 a.

In some embodiments, the blowing agent consists essentially of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate, and HFC-152 a. In some embodiments, the blowing agent consists of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate and HFC-152 a.

In some embodiments, the blowing agent comprises:

about 75% to about 85% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene; and

from about 15% to about 25% by weight of methyl formate.

In some embodiments, the blowing agent comprises:

about 10% to about 95% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene; and

from about 5% to about 40% by weight of methyl formate.

In some embodiments, the blowing agent comprises:

about 30% to about 85% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene; and

from about 10% to about 40% by weight of methyl formate.

In some embodiments, the blowing agent comprises:

about 20% to about 60% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene; and

from about 5% to about 25% by weight of methyl formate.

In some embodiments, the blowing agent comprises:

about 20% to about 55% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene; and

from about 5% to about 45% by weight of methyl formate.

In some embodiments, the blowing agent comprises:

about 20% to about 55% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene; and

from about 10% to about 25% by weight of methyl formate.

In some embodiments, the blowing agent comprises:

about 20% to about 55% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene;

from about 5% to about 45% by weight of methyl formate; and

from about 30% to about 70% by weight of HFC-152 a.

In some embodiments, the blowing agent comprises:

about 20% to about 55% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene;

from about 10% to about 25% by weight of methyl formate; and

from about 30% to about 70% by weight of HFC-152 a.

In some embodiments, the blowing agent comprises about 80 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and about 20 weight percent methyl formate.

In some embodiments, the blowing agent comprises:

about 30% to about 45% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene;

from about 15% to about 35% by weight of methyl formate; and

from about 30% to about 45% by weight of HFC-152 a.

In some embodiments, the blowing agent comprises:

about 30% to about 40% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene;

from about 20% to about 35% by weight of methyl formate; and

from about 30% to about 40% by weight of HFC-152 a.

In some embodiments, the blowing agent comprises:

about 35% to about 45% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene;

from about 15% to about 25% by weight of methyl formate; and

from about 35% to about 45% by weight of HFC-152 a.

In some embodiments, the blowing agent comprises:

about 30% to about 35% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene;

from about 30% to about 35% by weight of methyl formate; and

from about 30% to about 35% by weight of HFC-152 a.

In some embodiments, the blowing agent comprises about 40 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, about 20 weight percent methyl formate, and about 40 weight percent HFC-152 a.

In some embodiments, the blowing agent comprises about 33 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, about 33 weight percent methyl formate, and about 33 weight percent HFC-152 a.

In some embodiments, the method of the present invention further comprises heating the polymer and blowing agent in the presence of one or more additives. Exemplary additives include, but are not limited to, nucleating agents, cell stabilizers, surfactants, preservatives, antioxidants, reinforcing agents, fillers, antistatic agents, IR attenuating agents, extrusion aids, plasticizers, and viscosity modifiers, or any combination thereof, in amounts to achieve the desired effect.

In some embodiments, the blowing agents provided herein are substantially free of additives. In some embodiments, the blowing agents provided herein comprise one or more additives (e.g., one, two, three, four, or five additives).

In some embodiments, the process of the present invention is carried out in the presence of a nucleating agent. In some embodiments, the nucleating agent is selected from talc, graphite, and magnesium silicate.

In some embodiments, the foamable composition further comprises a flame retardant. In some embodiments, the flame retardant comprises a polymeric flame retardant or a halogenated flame retardant. In some embodiments, the flame retardant is a brominated flame retardant or a chlorinated flame retardant. In some embodiments, the flame retardant is a brominated styrene-butadiene block copolymer. One example of a brominated styrene-butadiene block copolymer is known commercially as PolyFR.

In some embodiments, the foamable composition further comprises an infrared attenuating agent.

As used herein, the term "molten composition" refers to a foamable composition. The amount of blowing agent in the molten composition will depend on the amount of additives other than blowing agent and the desired density in the foamed product. In some embodiments, the amount of blowing agent in the foamable composition is from 5 wt% to 20 wt%. In some embodiments, the amount of blowing agent in the foamable composition is from 5 wt% to 15 wt%, based on the weight of the foamable composition. It is understood that the weight percent of blowing agent in the foamable composition can be adjusted based on the desired density of the foam and the ratio of components in the blowing agent.

In some embodiments, the blowing agent is from about 5 parts to about 25 parts by mass per hundred parts of polymer, such as from about 5 parts to about 20 parts, from about 5 parts to about 15 parts, from about 5 parts to about 10 parts, from about 10 parts to about 25 parts, from about 10 parts to about 20 parts, from about 10 parts to about 15 parts, from about 15 parts to about 25 parts, from about 15 parts to about 20 parts, or from about 20 parts to about 25 parts by mass per hundred parts of polymer. In some embodiments, the blowing agent is from about 7 parts to about 18 parts per hundred parts by mass of polymer.

In some embodiments, the thermoplastic polymers provided herein are alkenyl aromatic polymers. As used herein, the term "alkenyl aromatic polymer" refers to a polymer formed from alkenyl-aromatic monomeric units. In some embodiments, the alkenyl-aromatic monomeric unit is C_2-6alkenyl-C_6-10An aryl monomer unit. In some embodiments, the alkenyl-aromatic monomeric unit is C_2-6Alkenyl-phenyl monomeric units wherein the phenyl group is optionally substituted. In some embodiments, the alkenyl aromatic polymer is polystyrene.

The polystyrene may be a homopolymer of styrene or may contain comonomers other than styrene (i.e., a polystyrene copolymer). In some embodiments, the thermoplastic polymer comprises a blend of polystyrene and an additional thermoplastic polymer. In some embodiments, the additional thermoplastic polymer is a copolymer of styrene and a monomer other than styrene (e.g., acrylonitrile).

In some embodiments, the thermoplastic polymer is selected from the group consisting of polystyrene, polyethylene copolymers, polypropylene copolymers, acrylonitrile butadiene styrene, styrene acrylonitrile copolymers, and blends thereof. In some embodiments, the thermoplastic polymer is selected from the group consisting of polystyrene, polyethylene, and polypropylene. In some embodiments, the thermoplastic polymer is a polyethylene-polypropylene copolymer. In some embodiments, the thermoplastic polymer is polystyrene.

Whether the thermoplastic polymer being foamed is polystyrene or a blend of polystyrene with other thermoplastic polymers, styrene is preferably the predominant polymerized monomer (unit) in the thermoplastic polymer being foamed. In some embodiments, polymerized units of styrene comprise at least 70 mol%, at least 80 mol%, at least 90 mol%, or at least 100 mol% of polymerized monomer units of the thermoplastic polymer.

When the thermoplastic polymer comprises a styrene copolymer, the amount of additional monomer copolymerized with styrene is such that the styrene content of the copolymer is at least 60 mol% of the copolymer, at least 70 mol%, at least 80 mol%, or at least 90 mol% of the copolymer, based on the total moles of copolymer (i.e., 100%). It should be understood that these ratios are applicable whether the styrene copolymer is merely a styrene-containing polymer of the thermoplastic polymers or a blend with other thermoplastic polymers, such as styrene homopolymer or other styrene copolymers.

In some embodiments, the thermoplastic polymer comprises a styrene homopolymer (i.e., a polystyrene homopolymer). When the thermoplastic polymer is a blend of polystyrene and other thermoplastic polymers as described above, the polystyrene component of the blend is preferably a styrene homopolymer comprising at least 80 wt% of the combined weight of polystyrene and other thermoplastic polymers.

The molecular weight of the thermoplastic polymer comprising polystyrene being foamed is sufficiently high to provide the necessary strength for the foam application requirements. The strength requirement determines the minimum density of the foamed product. The high molecular weight of the thermoplastic polymer comprising polystyrene also contributes to the strength of the foamed product. An indicator of molecular weight is the rate at which molten polymer flows through a defined orifice under a defined load. The lower the flow rate, the higher the molecular weight. Melt flow rate measurements were determined according to ASTM D1238 at 200 ℃ and using a 5kg weight on molten polymer. The weight of the molten polymer flowing through the orifice over a defined amount of time enables the melt flow rate to be reported in g/10 min. Preferably, the thermoplastic polymer comprising polystyrene has a melt flow rate of no greater than 20g/10min, more preferably no greater than 15g/10min, and most preferably no greater than 10g/10 min. Surprisingly, the higher the molecular weight (the lower the melt flow rate), the better the foaming result, especially with respect to accessibility to the low density foamed product, while still obtaining a smooth skin on the foamed product. Preferably, the minimum melt flow rate of all melt flow rates disclosed herein is at least 1g/10min, whereby the melt flow rate ranges disclosed herein include, but are not limited to, 1 to 25, 1 to 20, 1 to 15, and 1 to 10g/10 min. In some embodiments, the melt flow rate is about 25g/10min or less as determined according to the procedure of ASTM D1238 using a 5kg weight on molten polymer at 200 ℃.

The reference to thermoplastic polymers comprising polystyrene also applies to polystyrene itself. Thus, for example, the thermoplastic polymers comprising polystyrene disclosed in the preceding paragraphs may be replaced by the disclosed polystyrene.

In some embodiments, the process of the present invention further comprises extruding a thermoplastic polymer to form a thermoplastic polymer foam comprising Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate, and optionally HFC-152 a.

In some embodiments, extrusion is performed at a die temperature of about 100 ℃ to about 150 ℃, e.g., about 100 ℃ to about 140 ℃, about 100 ℃ to about 130 ℃, about 100 ℃ to about 120 ℃, about 100 ℃ to about 110 ℃, about 110 ℃ to about 150 ℃, about 110 ℃ to about 140 ℃, about 110 ℃ to about 130 ℃, about 110 ℃ to about 120 ℃, about 120 ℃ to about 150 ℃, about 120 ℃ to about 140 ℃, about 120 ℃ to about 130 ℃, about 130 ℃ to about 150 ℃, about 130 ℃ to about 140 ℃, or about 140 ℃ to about 150 ℃. In some embodiments, the extrusion is conducted at a die temperature of about 110 ℃ to about 140 ℃. In some embodiments, the extrusion is conducted at a die temperature of about 120 ℃ to about 130 ℃.

In some embodiments, the process of the present invention is carried out in an extruder to 1) form the foamable composition into a desired form; and 2) extruding the foamable composition to form a thermoplastic polymer foam comprising Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate, and optionally HFC-152 a.

When the process of the invention is carried out in an extruder, the thermoplastic polymer forms the feed to the extruder. The blowing agent and co-blowing agent are preferably fed into the extruder at a location intermediate the feed end and the extrusion end of the extruder, typically into a foamable composition produced as the extrusion screw advances the feed along the length of the extruder. Additional additives may be added where convenient and as may be determined by the state of the additives. For example, the solid additive may conveniently be added to the feed end of an extruder, possibly fed to the extruder as a mixture with the polymer feed in particulate form. The resulting foamable composition within the extruder is extruded through a die, thereby expanding the foamable composition into a foamed product (e.g., sheet, plate, rod, or tube) of a desired shape, and then cooled.

In the zone where the composition is melted within the extruder to form a molten composition, the melting is performed by the input of heat and the generation of heat during the mixing process to form the melt, which is considered to be the melt mixing zone. In one embodiment, the temperature is at least 185 ℃, more preferably at least 190 ℃ or at least 200 ℃ or at least 210 ℃. In some embodiments, the maximum temperature of all melt mixing temperatures disclosed herein is 250 ℃. The melt mixing temperature disclosed herein is the melt temperature in the mixing zone at the time of mixing. In some embodiments, melt mixing is carried out at a pressure of at least 3000psi (207 bar), more preferably at least 3500psi (241 bar), more preferably at least 4000psi (276 bar). In some embodiments, the maximum of all minimum pressures disclosed at which melt mixing is performed is no greater than 5000psi (345 bar). The pressures disclosed herein are gauge pressures.

In the zone within the extruder where the molten composition is extruded, the molten composition is cooled such that the temperature at which the extrusion is carried out is preferably at least 105 ℃, more preferably 110 ℃, more preferably at least 125 ℃. In some embodiments, the maximum value of all minimum extrusion temperatures disclosed herein is preferably no greater than 140 ℃. The extrusion temperatures disclosed herein are the temperatures of the melt at the time of extrusion.

In some embodiments, extrusion is preferably performed at a pressure of at least 1500psi (103 bar), more preferably at least 1600psi (110 bar). The maximum value of the minimum extrusion pressure disclosed herein is preferably no greater than 2000psi (138 bar). The extrusion pressure is the pressure inside the extrusion die.

In some embodiments, the process is conducted at a pressure immediately prior to foaming of from about 100psi to about 5000psi, such as from about 100psi to about 4000psi, from about 100psi to about 3000psi, from about 100psi to about 2000psi, from about 100psi to about 1000psi, from about 1000psi to about 5000psi, from about 1000psi to about 4000psi, from about 1000psi to about 3000psi, from about 1000psi to about 2000psi, from about 2000psi to about 5000psi, from about 2000psi to about 4000psi, from about 2000psi to about 3000psi, from about 3000psi to about 5000psi, from about 3000psi to about 4000psi, or from about 4000psi to about 5000 psi. In some embodiments, the process is carried out at a pressure of about 500psi to about 4000psi immediately prior to foaming. In some embodiments, the process is carried out at a pressure of about 800psi to about 3000psi immediately prior to foaming. In some embodiments, the process is carried out at a pressure of about 1000psi to about 2500psi immediately prior to foaming.

The various ranges disclosed above for melt flow rate, temperature and pressure may be used in the practice of the present invention in any combination to achieve the particular foamed structure desired. For example, melt mixing pressures of 3000 to 5000psi (207 to 345 bar) are preferred to achieve low foam densities for foamed products, and this temperature range can be used with any of the melt mixing and extrusion temperature ranges to form any of the smooth-skinned, closed-cell foam product densities disclosed herein. The same is true for melt extrusion pressures ranging from 1500 to 2000psi (103 to 138 bar) along with 3000 to 5000psi (207 to 345 bar) for melt mixing. Most preferably, two preferred pressure ranges of melt mixing (207 to 345 bar) and extrusion (103 to 138 bar) are used together. Depending on the desired foamed product result, melt flow rates of no more than 25, 20, 15 and 10 and only at least 1 (all values being g/10min) of the foamed polymer may be used with any of these combinations of pressure and temperature.

When the process of the invention is carried out in an extruder, the thermoplastic polymer (i.e. foamable composition) is cooled such that the temperature at which extrusion is carried out is preferably at least 125 ℃ and more preferably at least 130 ℃. In some embodiments, the temperature at which the extrusion is carried out is a temperature that is lower than the first temperature of the process of the present invention. In some embodiments, all minimum extrusion temperatures disclosed herein have a maximum value of about 150 ℃ or less. In some embodiments, the extrusion is performed at a temperature of about 100 ℃ to about 150 ℃. In some embodiments, the extrusion is performed at a temperature of about 110 ℃ to about 140 ℃.

In some embodiments, the extrusion temperature disclosed herein is the temperature of the polymer melt at the time of extrusion.

When the process of the invention is carried out in an extruder, the extrusion is preferably carried out at a pressure of at least 1500psi (103 bar) and more preferably at least 1600psi (110 bar). The maximum value of the minimum extrusion pressure disclosed herein is preferably no greater than 2000psi (138 bar). In some embodiments, the extrusion is performed at a pressure of about 1500psi to about 2000 psi. In some embodiments, the extrusion pressure disclosed herein is the pressure inside the extrusion die.

In some embodiments, the extrusion is performed at a pressure of about 100psi to about 5000psi, such as about 100psi to about 4000psi, about 100psi to about 2000psi, about 100psi to about 1000psi, about 1000psi to about 5000psi, about 1000psi to about 4000psi, about 1000psi to about 2000psi, about 2000psi to about 5000psi, about 2000psi to about 4000psi, or about 4000psi to about 5000 psi.

In some embodiments, the extrusion is performed at a pressure of about 500psi to about 4000 psi.

In some embodiments, the extrusion is conducted at a pressure of from about 750psia to about 3000 psia.

In some embodiments, the extrusion is conducted at a pressure of from about 900psia to about 2750 psia.

In some embodiments, the present application provides a foamed product (e.g., a thermoplastic polymer foam) prepared according to one or more of the methods described herein.

In some embodiments, the foam comprises:

(b) blowing agents provided herein (i.e., blowing agents comprising Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate, and optionally HFC-152 a).

In some embodiments, the foam comprises:

(b) a blowing agent as provided herein, comprising Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and methyl formate.

In some embodiments, the foam comprises:

(b) a blowing agent as provided herein, comprising Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate and HFC-152 a.

In some embodiments, the foams provided herein further comprise one or more additives described herein.

It should be understood that the blowing agent blends, additives, melt flow rates, temperatures, pressures, and other process parameters described herein may be used in any combination in the practice of the present invention to achieve the particular foamed structure desired.

In some embodiments, the thermoplastic polymer foams provided herein comprise one or more of the following properties:

closed cell-at least 70%, at least 80%, at least 90% or at least 95%. The closed cell content can be measured according to ASTM method D6226-05.

Average cell size; from about 0.005mm to about 5mm (i.e., 5 μm to about 5000 μm), such as from about 0.01mm to about 5mm, from about 0.05mm to about 0.5 mm. In some embodiments, the average cell size is from about 0.01mm to about 1 mm. In some embodiments, the average cell size is from about 0.02mm to about 0.5 mm. In some embodiments, the average cell size is from about 0.1mm to about 0.3 mm.

A density of not more than about 40kg/m³Not more than about 35kg/m³Or not more than about 23kg/m³. The density can be measured according to ISO method 84585.

Smooth epidermis.

Substantially free of air voids.

Examples

The present invention will be described in more detail by way of specific examples. The following examples are provided for illustrative purposes and are not intended to limit the invention in any way.

Example 1 solubility of HFO-1336 mzz-Z/methyl formate blends in softened polystyrene homopolymer

This example demonstrates the enhanced solubility of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene (i.e., HFO-1336 mzz-Z)/methyl formate blends in softened polystyrene as compared to the solubility of pure HFO-1336mzz-Z in softened polystyrene.

The solubility of HFO-1336mzz-Z and HFO-1336 mzz-Z/methyl formate blends containing 20% by weight methyl formate in softened polystyrene was determined by the following procedure: 78g of polystyrene was loaded on stainless steel

In a reactor. The reactor was weighed, fitted to the inlet/outlet tube, immersed in an oil bath and evacuated. An amount of blowing agent in excess of its intended solubility was loaded into the evacuated reactor using a HIP Pressure generator (manufactured by High Pressure Equipment Company). The oil bath was heated and held at a temperature of 179 ℃ for 30 minutes, and then the final pressure was recorded. Will be provided with

The reactor was removed from the oil bath and cooled to room temperature. After allowing excess (polystyrene insoluble) blowing agent to drain or vent, the reactor (with re-solidified polystyrene inside) is weighed. Weight gain is reported as solubility according to the following formula:

equation 1；

Solubility (phr) — (resin weight gain ÷ 78) × 100.

As shown in FIG. 1, it has been unexpectedly discovered that blends of HFO-1336mzz-Z with methyl formate exhibit a solubility in softened polystyrene that significantly exceeds the solubility of pure HFO-1336mzz-Z under the same conditions. For example, the solubility of pure HFO-1336mzz-Z in a softened polystyrene homopolymer having a Melt Flow Index (MFI) of 5.0g/10min at 179 ℃ and 1,682psia was measured as 5.82g/100g of polystyrene (i.e., 5.82 phr). In contrast, HFO-1336 mzz-Z/methyl formate blends containing 20 wt.% methyl formate exhibited a solubility of 13.14g/100g of polystyrene in the same polystyrene at the same temperature and pressure or 125.7% higher than the solubility of pure HFO-1336 mzz-Z.

Example 2 solubility of HFO-1336 mzz-Z/methyl formate blends in softened polystyrene homopolymer

This example demonstrates the enhanced solubility of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene (i.e., HFO-1336mzz-Z)/HFC-152 a/methyl formate blends in softened polystyrene compared to the solubility of HFO-1336mzz-Z/HFC-152a blends in softened polystyrene homopolymer. The solubility analysis was performed according to the general procedure described in example 1.

As shown in fig. 2, it was unexpectedly found that ternary blends of HFO-1336mzz-Z/HFC-152 a/methyl formate (e.g., 40%/20% by weight and 33.33%/33.33% by weight, respectively) exhibit solubilities in softened polystyrene that significantly exceed the solubilities of binary blends of HFO-1336 mzz/HFC-152 a (50%/50% by weight) under the same conditions.

For example, a 50 wt%/50 wt% HFO-1336mzz-Z/HFC-152a blend has a solubility of 9.58g/100g polystyrene (i.e., 9.58phr) in a softened polystyrene homopolymer having a Melt Flow Index (MFI) of 5.0g/10min at 179 ℃ and 1,336 psia. In contrast, the solubility of the ternary HFO-1336mzz-Z/HFC-152 a/methyl formate (40 wt%/20 wt%, respectively) exhibits a solubility in the same polystyrene of about 12.80g/100g or 33.61% greater than the solubility of the binary HFO-1336mzz-Z/HFC-152a blend at the same temperature and the same pressure. The solubility of the ternary HFO-1336mzz-Z/HFC-152 a/methyl formate (33.33 wt%/33.33 wt%) blend exhibited a solubility of about 16.25g/100g polystyrene in the same polystyrene or 69.62% higher than the solubility of the binary HFO-1336mzz-Z/HFC-152a blend at the same temperature and the same pressure.

Other embodiments

1. In some embodiments, the present application provides a method for preparing a thermoplastic polymer foam, the method comprising:

2. The method of embodiment 1 wherein the blowing agent has a solubility in the polymer that is greater than the solubility of the Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene alone in the polymer.

3. The method of embodiment 1 or 2, wherein the blowing agent comprises from about 75% to about 85% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

4. The method of embodiment 1 or 2, wherein the blowing agent comprises about 80% by weight Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

5. The method of any of embodiments 1-4, wherein the blowing agent comprises from about 15 wt.% to about 25 wt.% methyl formate.

6. The method of any of embodiments 1-4, wherein the blowing agent comprises about 20 wt.% methyl formate.

7. The method of any of embodiments 1-6 wherein the blowing agent consists essentially of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and methyl formate.

8. The method of embodiments 1 or 2, wherein the blowing agent further comprises HFC-152 a.

9. The method of embodiment 8 wherein the blowing agent has a solubility in the polymer that is greater than the solubility of the mixture of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and HFC-152a in the polymer.

10. The method of embodiment 8 or 9, wherein the blowing agent comprises from about 30% to about 45% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

11. The method of embodiment 8 or 9, wherein the blowing agent comprises from about 30% to about 40% by weight Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

12. The method of any of embodiments 8-11, wherein the blowing agent comprises from about 15 wt.% to about 35 wt.% methyl formate.

13. The method of any of embodiments 8-11, wherein the blowing agent comprises from about 20 wt.% to about 35 wt.% methyl formate.

14. The method of any of embodiments 8-13, wherein the blowing agent comprises from about 30 wt% to about 45 wt% HFC-152 a.

15. The method of any of embodiments 8-13, wherein the blowing agent comprises from about 30 wt% to about 40 wt% HFC-152 a.

16. The method of any of embodiments 8-15, wherein the blowing agent consists essentially of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate, and HFC-152 a.

17. The method of any of embodiments 1-16, wherein the thermoplastic polymer is an alkenyl aromatic polymer.

18. The method of any of embodiments 1-16, wherein the thermoplastic polymer is selected from the group consisting of: polystyrene, polyethylene homopolymers, polyethylene, polypropylene homopolymers, polypropylene, acrylonitrile butadiene styrene, and styrene acrylonitrile copolymers, and blends thereof.

19. The method of any of embodiments 1-16, wherein the thermoplastic polymer is selected from the group consisting of: polystyrene homopolymers, polystyrene copolymers, styrene-acrylonitrile copolymers, and blends thereof.

20. The process of any one of embodiments 1 to 19, wherein the process is carried out at a pressure of about 100psi to about 5000psi immediately prior to foaming.

21. The process of any one of embodiments 1 to 19, wherein the process is conducted at a pressure of about 750psi to about 2500psi immediately prior to foaming.

22. The method of any one of embodiments 1-21, further comprising extruding the thermoplastic polymer to form the thermoplastic polymer foam.

23. The method of embodiment 21, wherein the extruding is conducted at a die temperature of about 100 ℃ to about 150 ℃.

24. The method of embodiment 21, wherein the extruding is conducted at a die temperature of about 110 ℃ to about 140 ℃.

25. The method of embodiment 21, wherein the extruding is conducted at a die temperature of about 120 ℃ to about 130 ℃.

26. The method of any one of embodiments 1 to 25, wherein the polymer foam is a closed cell polymer foam.

27. The method of any one of embodiments 1 to 26, wherein the polymer comprises at least 70% closed cells.

28. The method of any one of embodiments 1 to 27, wherein the polymer foam is a smooth-skinned polymer foam.

29. The method of any one of embodiments 1 to 28, wherein the polymer foam is substantially free of air cells.

30. The method of any one of embodiments 1 to 29, wherein the polymer is a polystyrene homopolymer.

31. The process of any of embodiments 1-30, wherein the foamable composition further comprises a nucleating agent.

32. The method of embodiment 31, wherein the nucleating agent is selected from the group consisting of talc, graphite, and magnesium silicate.

33. The method of any of embodiments 1-32, wherein the foamable composition further comprises a flame retardant.

34. The method of embodiment 33, wherein the flame retardant comprises a polymeric flame retardant or a halogenated flame retardant.

35. The method of embodiment 33, wherein the flame retardant is a brominated flame retardant or a chlorinated flame retardant.

36. The method of embodiment 33, wherein the flame retardant is a brominated styrene-butadiene block copolymer.

37. The process of any of embodiments 1 through 36, wherein the foamable composition further comprises an infrared attenuating agent.

38. The method of any of embodiments 1-37, wherein the blowing agent is from about 1 part to about 25 parts per hundred parts by mass of polymer.

39. The method of any of embodiments 1-37, wherein the blowing agent is from about 7 parts to about 18 parts per hundred parts by mass of polymer.

40. In some embodiments, the present application provides a thermoplastic polymer foam comprising:

(b) a blowing agent comprising from about 95% to about 1% by weight Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and from about 1% to about 95% by weight methyl formate.

41. The thermoplastic polymer foam of embodiment 40, wherein the blowing agent comprises from about 75% to about 85% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

42. The thermoplastic polymer foam of embodiment 40, wherein the blowing agent comprises about 80 weight percent Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

43. The thermoplastic polymer foam of any of embodiments 40-42, wherein the blowing agent comprises from about 15 wt.% to about 25 wt.% methyl formate.

44. The thermoplastic polymer foam of any of embodiments 40-42, wherein the blowing agent comprises about 20 wt methyl formate.

45. The thermoplastic polymer foam of any of embodiments 40-44, wherein the blowing agent consists essentially of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene and methyl formate.

46. The thermoplastic polymer foam of embodiment 40, wherein the blowing agent further comprises HFC-152 a.

47. The thermoplastic polymer foam of embodiment 46, wherein the blowing agent comprises from about 30% to about 45% by weight of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

48. The thermoplastic polymer foam of embodiment 46, wherein the blowing agent comprises from about 30% to about 40% by weight Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene.

49. The thermoplastic polymer foam of any one of embodiments 46-48, wherein the blowing agent comprises from about 15 wt.% to about 35 wt.% methyl formate.

50. The thermoplastic polymer foam of any one of embodiments 46-48, wherein the blowing agent comprises from about 20 wt.% to about 35 wt.% methyl formate.

51. The thermoplastic polymer foam of any of embodiments 46-50, wherein the blowing agent comprises from about 30 wt% to about 45 wt% HFC-152 a.

52. The thermoplastic polymer foam of any of embodiments 46-50, wherein the blowing agent comprises from about 30 wt% to about 40 wt% HFC-152 a.

53. The thermoplastic polymer foam of any of embodiments 46-52, wherein the blowing agent consists essentially of Z-1, 1, 1, 4, 4, 4-hexafluoro-2-butene, methyl formate, and HFC-152 a.

54. The thermoplastic polymer foam of any of embodiments 40-53, wherein the foam has less than about 64kg/m according to ISO method 845-85³The density of (c).

55. The thermoplastic polymer foam of any of embodiments 40-53, wherein the foam has less than about 30kg/m according to ISO method 845-85³The density of (c).

56. The thermoplastic polymer foam of any of embodiments 40-55, wherein the polymer has a melt flow rate of less than about 25g/10 min.

57. The thermoplastic polymer foam of any one of embodiments 40 to 56, which is a closed cell polymer foam.

58. The thermoplastic polymer foam of any one of embodiments 40 to 57, which is a smooth skinned polymer foam.

59. The thermoplastic polymer foam of any one of embodiments 40 to 58, wherein the polymer foam is substantially free of air cells.

60. The thermoplastic polymer foam of any one of embodiments 40 to 59, wherein the foam comprises at least 70% closed cells.

61. The thermoplastic polymer foam of any of embodiments 40-60, wherein the foam has an average cell size of from about 1 micron to about 5,000 microns.

62. The thermoplastic polymer foam of any of embodiments 40-60, wherein the foam has an average cell size of from about 10 microns to about 5,000 microns.

63. The thermoplastic polymer foam of any of embodiments 40-62, wherein the foam has an average cell size of from about 100 microns to about 300 microns.

64. The thermoplastic polymer foam of any one of embodiments 40-63, wherein the foam is a polystyrene foam.

65. The thermoplastic polymer foam of any one of embodiments 40-63, wherein the foam is a styrene/acrylonitrile copolymer foam.

66. The thermoplastic polymer foam of any of embodiments 40-65, wherein the foam has about 40kg/m³Or a lower density.

It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims. It will be understood by those of ordinary skill in the art to which the invention relates that any feature described herein in relation to any particular aspect and/or embodiment of the invention may be combined with one or more of any other feature of any other aspect and/or embodiment of the invention described herein, as appropriate, with modifications to ensure compatibility of the combination. Such combinations are considered part of the invention contemplated by this disclosure.

Claims

1. A method for preparing a thermoplastic polymer foam, the method comprising:

(a) providing a foamable composition comprising a thermoplastic polymer and a blowing agent, wherein the blowing agent comprises from about 30% to about 85% by weight of Z-1,1,1,4,4,4- hexafluoro-2-butene and about 10% to about 40% by weight methyl formate; and

2. The method of claim 1, wherein the blowing agent has a greater solubility in the polymer than the Z-1,1,1,4,4,4-hexafluoro-2-butene alone Solubility in the polymer.

3. The method of claim 1, wherein the blowing agent comprises from about 75% to about 85% by weight Z-1,1,1,4,4,4-hexafluoro-2-butene.

4. The method of claim 1, wherein the blowing agent comprises about 80% by weight of Z-1,1,1,4,4,4-hexafluoro-2-butene.

5. The method of claim 1, wherein the blowing agent comprises from about 15% to about 25% by weight methyl formate.

6. The method of claim 1, wherein the blowing agent comprises about 20% by weight methyl formate.

7. The method of claim 1, wherein the blowing agent consists essentially of Z-1,1,1,4,4,4-hexafluoro-2-butene and methyl formate.

8. The method of claim 1, wherein the blowing agent further comprises HFC-152a.

9. The method of claim 8, wherein the solubility of the blowing agent in the polymer is greater than that of Z-1,1,1,4,4,4-hexafluoro-2-butene and HFC- The solubility of the mixture of 152a in the polymer.

10. The method of claim 8, wherein the blowing agent comprises from about 30% to about 45% by weight of Z-1,1,1,4,4,4-hexafluoro-2-butene.

11. The method of claim 8, wherein the blowing agent comprises from about 30% to about 40% by weight of Z-1,1,1,4,4,4-hexafluoro-2-butene.

12. The method of claim 8, wherein the blowing agent comprises from about 15% to about 35% by weight methyl formate.

13. The method of claim 8, wherein the blowing agent comprises from about 20% to about 35% by weight methyl formate.

14. The method of claim 8, wherein the blowing agent comprises from about 30% to about 45% by weight HFC-152a.

15. The method of claim 8, wherein the blowing agent comprises from about 30% to about 40% by weight HFC-152a.

16. The method of claim 8, wherein the blowing agent consists essentially of Z-1,1,1,4,4,4-hexafluoro-2-butene, methyl formate, and HFC-152a .

17. The method of claim 1, wherein the thermoplastic polymer is an alkenyl aromatic polymer.

18. The method of claim 1, wherein the thermoplastic polymer is selected from the group consisting of polystyrene, polyethylene, polyethylene copolymers, polypropylene, polypropylene copolymers, acrylonitrile butadiene Styrene, and styrene-acrylonitrile copolymers, and blends thereof.

19. The method of claim 1, wherein the thermoplastic polymer is selected from the group consisting of polystyrene homopolymers, polystyrene copolymers, styrene-acrylonitrile copolymers, and blends thereof thing.

20. The method of claim 1, wherein the method is performed at a pressure immediately prior to foaming of from about 100 psi to about 5000 psi.

21. The method of claim 1, wherein the method is performed at a pressure immediately prior to foaming from about 750 psi to about 2500 psi.

22. The method of claim 1, further comprising extruding the thermoplastic polymer to form the thermoplastic polymer foam.

23. The method of claim 22, wherein the extrusion is performed at a die temperature of about 100°C to about 150°C.

24. The method of claim 22, wherein the extrusion is performed at a die temperature of about 110°C to about 140°C.

25. The method of claim 22, wherein the extrusion is performed at a die temperature of about 120°C to about 130°C.

26. The method of claim 1, wherein the polymer foam is a closed cell polymer foam.

27. The method of claim 26, wherein the polymer comprises at least 70% closed cells.

28. The method of claim 26, wherein the polymer foam is a smooth skin polymer foam.

29. The method of claim 26, wherein the polymeric foam is substantially free of air cells.

30. The method of claim 1, wherein the polymer is a polystyrene homopolymer.

31. The method of claim 1, wherein the foamable composition further comprises a nucleating agent.

32. The method of claim 31, wherein the nucleating agent is selected from the group consisting of talc, graphite, and magnesium silicate.

33. The method of claim 1, wherein the foamable composition further comprises a flame retardant.

34. The method of claim 33, wherein the flame retardant comprises a polymeric flame retardant or a halogenated flame retardant.

35. The method of claim 33, wherein the flame retardant is a brominated flame retardant or a chlorinated flame retardant.

36. The method of claim 33, wherein the flame retardant is a brominated styrene-butadiene block copolymer.

37. The method of claim 1, wherein the foamable composition further comprises an infrared attenuator.

38. The method of claim 1, wherein the blowing agent is from about 1 part to about 25 parts by mass per hundred parts polymer.

39. The method of claim 1, wherein the blowing agent is from about 7 parts to about 18 parts by mass per hundred parts polymer.

40. A thermoplastic polymer foam comprising:

(a) a thermoplastic polymer selected from the group consisting of polystyrene homopolymers, polystyrene copolymers, and styrene-acrylonitrile copolymers, or blends thereof; and

(b) a blowing agent comprising 30% to 85% by weight of Z-1,1,1,4,4,4-hexafluoro-2-butene and 10% to 40% by weight of Z-1,1,1,4,4,4-hexafluoro-2-butene of methyl formate.

41. The thermoplastic polymer foam of claim 40, wherein the blowing agent further comprises HFC-152a.

42. The thermoplastic polymer foam of claim 40, wherein the foam has a density of less than about 64 kg/ ^m3 according to ISO method 845-85.

43. The thermoplastic polymer foam of claim 40, wherein the foam has a density of less than about 30 kg/ ^m3 according to ISO method 845-85.

44. The thermoplastic polymer foam of claim 40, wherein the polymer has a melt flow rate of less than about 25 g/10 min.

45. The thermoplastic polymer foam of claim 40, which is a closed cell polymer foam.

46. The thermoplastic polymer foam of claim 40, which is a smooth skin polymer foam.

47. The thermoplastic polymer foam of claim 45, wherein the polymer foam is substantially free of cells.

48. The thermoplastic polymer foam of claim 40, wherein the foam comprises at least 70% closed cells.

49. The thermoplastic polymer foam of claim 48, wherein the foam has an average cell size of from about 1 micron to about 5,000 microns.

50. The thermoplastic polymer foam of claim 48, wherein the foam has an average cell size of from about 10 microns to about 5,000 microns.

51. The thermoplastic polymer foam of claim 48, wherein the foam has an average cell size of from about 100 microns to about 300 microns.

52. The thermoplastic polymer foam of claim 40, wherein the foam is polystyrene foam.

53. The thermoplastic polymer foam of claim 40, wherein the foam is a styrene/acrylonitrile copolymer foam.

54. The thermoplastic polymer foam of claim 40, wherein the foam has a density of about 40 kg/ ^m3 or less.